A new Nature study followed paired tumor samples from 183 people with IDH-mutant glioma and found that recurrence does not have one molecular script. Oligodendrogliomas tended to acquire PI3K and NOTCH1 mutations associated with a higher mutation burden. Astrocytomas instead acquired focal oncogene amplifications and CDKN2A/B deletions associated with chromosomal imbalance, chromosome shattering and whole-genome doubling. Temozolomide left mutational signatures in both types; a radiotherapy-associated signature rose specifically in astrocytomas. The useful advance is a map of divergent evolution that may eventually support treatment stratification—not evidence that a new therapy already works. Nature, Oct. 14 · Yale School of Medicine